This is my website: Aviene.pl. I have scanned it by the website valuation tool. My website is 2.9 years old (this is what that tool shows, and that's the truth) but unfortunately every tool shows that my PageRank is 0 or "no data". What should I do to make PageRank working on my website? Should I include a special script to make it work or maybe a file with some code on my server? Please help, I can`t find anything about this situation.
The visible PageRank that you will be able to access in any tool/browser extension (toolbar PageRank) has not been updated since December 2013.
It has been pretty much discontinued so don't expect it to update again in the future. There is no "official" announcement as such but it has come from Google that it is unlikely that it will be updated ever again.
Subsequently, any domains with no authority prior to the second half of 2013 will show as 0 PageRank or 'no data' if it has never been measured.
Focus your attention on much more worthwhile and meaningful metrics instead. PageRank was never a metric worth chasing in the first place which is part of the reason why Google have abandoned the public-facing instance of it.